At the end of 2011, after consultation with Mathieu and others,
Phaseit
sponsored PyPDF2
as a fork of pyPdf on
GitHub. The initial impetus was to
handle a wider range of input PDF instances; Phaseit's commercial
work often encounters PDF instances "in the wild" that it needs to
manage (mostly concatenate and paginate), but that deviate so much
from PDF standards that pyPdf can't read them. PyPDF2 reads a
considerably wider range of real-world PDF instances.

Neither pyPdf nor PyPDF2 aims to be universal, that is, to provide all
possible PDF-related functionality;
here
are descriptions of other PDF libraries, including Python-based ones.
Note that the similar-appearing
pyfpdf of Mariano
Reingart is most comparable
to ReportLab,
in that both ReportLab and pyfpdf emphasize document generation.
Interestingly enough, pyfpdf builds in a basic
HTML->PDF converter; while PyPDF2 has no knowledge of HTML,
HTML->PDF conversion is another interest
of Phaseit's.

So what is PyPDF2 truly about? Think about popular [document]
pdftk
for a moment. PyPDF2 does what pdftk does, and it does so within
your current Python process, and it handles a wider range of
variant PDF formats [explain]. PyPDF2 has its own
FAQ to answer other questions that
have arisen.

[Compare pyPdf and PyPDF2. Spelling. Technical details:
read; new functionality. Explain the other fork, and
pyfpdf.]

Plans for PyPDF2 include:

[much] more complete documentation--probably just a list of the entry points which PyPDF2 adds to pyPdf;

[explain status of port to Python3;]

PyPackaging [emphasize use with Zope/Plone [more references]];

[licensing [update]];

[re-do donation button for JS-less contexts]

[clean-up HTML5]

[... other ...].

Current plans for PyPDF2 do not include the ability to:

merge annotations [but explain we're thinking about it seriously];

...

Let us know if you think these targets should change.

[README, ...]

The Reddit /r/python crowd chatted obliquely and briefly about
PyPDF2 in March 2012.

pyPdf's
documentation applies; that is, PyPDF2 aims to be a strict superset
of pyPdf, doing everything that pyPdf's documentation claims for
pyPdf, but also a bit more.

What are the differences between the two libraries? There are
several cases where pyPdf tosses an (undocumented) exception,
and PyPDF2 either provides a more descriptive exception, or
simply returns a correct result.

PyPDF2 also extends pyPdf's application programming interface
in quite a few regards [strict/non-strict] [none of which we've yet documented ...]. However, in July 2012, Mike Driscoll
helpfully
explained parts of what we're doing.

In 2011, when Phaseit committed to long-term support of PyPDF2 as
an open-source project, GitHub seemed the most advantageous host
because of ...

You can retrieve PyPDF2 sources even without GitHub familiarity or
a GitHub account. If you have a command-line git client, you
can simply write git clone git://github.com/knowah/PyPDF2.git,
and copies of all the PyPDF2 sources will show up in the
PyPDF2 directory (folder) of your current
working directory (folder). On Debian-derived hosts, installation
of the client should be as easy as
sudo apt-get install git-core. [Explain wget,
Win* clients, ...]

Contact the PyPDF2 maintainers

We welcome questions or comment about PyPDF2 through e-mail to
PyPDF2@Phaseit.net.
Announcements about
PyPDF2 occasionally appear by way of
Twitter.

Behind the scenes, one of PyPDF2's strengths is its extensive
collection of test scripts (initiated by Mathieu with pyPdf).
These are "behind the scenes" because many of the
test instances are PDF files supplied by correspondents. If
PyPDF2 fails you in some way, please understand that you can
send us all artifacts--files, scripts, and so on--necessary
to reproduce the symptom, with confidence that we'll maintain
your confidentiality. That's how we are.

Along with the paid consulting that dominates our days, we're
happy to receive money donations in addition to updates, fault
reports, and so on; that is, if you send us money, make sure
to include at least a few words about your interest in PyPDF2,
so we can be sure to steer the project in your direction. As
of this writing, we've only implemented a donation button in
Dwolla; if PayPal makes a big difference to you, let us know,
and we'll provide that, too.